The present invention relates to a lens fitted film package, and more particularly to a lens fitted film package which is changeable as to its photographic magnification.
Lens fitted photographic film packages, which have become increasingly popular in recent years, have a patrone or cartridge containing a roll of film, a taking lens and a simple shutter structure which are packaged as a unit. For economy, such a lens fitted film package is provided with a single-element taking lens made of plastic and a viewfinder of simple construction such a direct-vision viewfinder. Such lens-fitted film packages provide photographers with trouble-free operation when taking pictures because there is no need to load and unload a film.
The lens-fitted film package, after the exposure of all frames of the film is forwarded to a photo shop or photo laboratory without removing the film. There, the exposed film in a film cartridge is removed by breaking open the film package and is then developed to make prints therefrom while the empty film package is scrapped. The prints together with the developed film are returned to the customer. The single-element taking lens of the lens-fitted film package, which usually has a focal length of about 35 mm, is suitable for standard or relatively wide-angle photography when the lens-fitted film package contains a 135-type roll film.
On the other hand, it is a recent tendency in conventional 35 mm compact cameras to employ a focal length changeable lens as the taking lens. Some of such focal length changeable lens include telephotographic conversion lenses which are moved into or out of the optical path of a taking lens having a focal length suitable for standard or relatively wide-angle photography. To move the conversion lens into and out of the optical path of the taking lens so as to change the focal length of the taking lens suitably for telephotography, it is necessary to incorporate a conversion lens moving mechanism in the 35 mm compact camera. Such a conversion lens moving mechanism is, however, too intricate, bulky and expensive to incorporate in the above-described lens-fitted film packages.